DENDRONUTRIENT · Disentangling the effects of CO2 fertilization, nutrient limitation and water availability on forest ecosystem processes: Estimating their long-term consequences on SW European forests

Disentangling the effects of CO2 fertilization, nutrient limitation and water availability on forest ecosystem processes: Estimating their long-term consequences on SW European forests

European forests will experience novel growth conditions for which no historical reference exist. To correctly predict the impact of global change we have to understand the long-term response of forest ecosystems to management under climate change. To do so, it is necessary to have long-term data from real forests combined with ecological models. Therefore, the overall objective of this project was to improve our understanding of future growth patterns on European forests. To do so, two Scots pine stands in northern Spain representing continental and Mediterranean climates have been used. These sites have provided long-term field data to produce three major data series: My results show that the response of SW European forests to changing growing conditions will depend on both the intensity of the change and the particular edaphic-topographic conditions of each forest stand. In Mediterranean, low-elevation forests, a reduction in growth is expected because the CO2 fertilization effect is not enough to compensate the growth reduction due to water stress. However, at these sites, the most limiting factor is nutrient availability, as forests stands are already acclimated to summer droughts. On the other hand, continental, high-elevation forests could benefit from increasing temperatures that will extend the growing season, although such positive effect could be limited by reductions in water availability, with CO2 fertilization being almost negligible (Figure Carbon). At these poor sites, as trees are already adapted to low availability of nutrients, water scarcity will be the most important limiting factor. The trees at the research forests have also shown the capacity to increase their efficiency of using nutrients to grow depending on the availability and temporal change of such nutrients (Figure Nitrogen). In fact, my work has shown that the changes in nutrient availability that trees experience during their lives are recorded in their wood, which can be used as a record of annual nutrient change (Figure PKCaMg). All things considered, my results indicate that SW European forestry needs to be locally adapted to take advantage of increasing growth potential in cool sites but at the same time reducing the negative effects of global change in warm sites.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз